Wednesday, August 6, 2014

Join the Live Discussion: The Hunt for Other Worlds Heats Up

Join the Live Discussion: The Hunt for Other Worlds Heats Up:



Artist’s impression of a massive asteroid belt in orbit around a star. Credit: NASA-JPL / Caltech / T. Pyle (SSC)

Artist’s impression of a massive asteroid belt in orbit around a star. Credit: NASA-JPL / Caltech / T. Pyle (SSC)


As readers of Universe Today know, exoplanets are one of the hottest topics in astronomy today. In just the past six months, astronomers have announced the discovery of more than 700 planets orbiting other stars, bringing the total to more than 1700. These discoveries include the first Earth-size planet found in what’s called the habitable zone of a star, where liquid water could exist; the oldest known planet that could support life; and the first rocky “mega-Earth,” a planet that’s much like Earth except that it’s 17 times more massive.


On July 9, at 19:00 UTC (3 pm EDT, 12:00 pm PDT), three exoplanet hunters will come together discuss the discovery boom, consider the next steps in the hunt for habitable worlds, and debate whether we’re likely to find alien life in the next decade.

You can watch live below:



The panel includes MIT’s Zachory Berta-Thompson, Stanford’s Bruce Macintosh and Université de Montréal’s Marie-Eve Naud) will come together discuss the recent discovery boom, consider the next steps in the hunt for habitable worlds, and ponder the odds of finding life on another planet. The discussion will be moderated by journalist Kellen Tuttle.

To submit questions ahead of time or during the webcast, send an email to info@kavlifoundation.org or post on Twitter with hashtag #KavliLive. You can find additional information about the webcast and the Kavli Foundation here.

Between the great combination of scientists and the exciting topic, this should be an especially good one.

About the Participants (left to right)

ZACHORY BERTA-THOMPSON – Dr. Berta-Thompson is the Torres Fellow for Exoplanetary Research at the MIT Kavli Institute for Astrophysics and Space Research. He hunts for exoplanets as a member of the MEarth Project, a survey to find small planets orbiting the closest, smallest stars.

BRUCE MACINTOSH – Dr. Macintosh is the principal investigator for the Gemini Planet Imager, which searches for planets from the Gemini South telescope. GPI recently snapped its first image, thereby producing the best-ever direct photo of a planet outside our solar system. Dr. Macintosh is also a Professor of Physics at Stanford University and a member of the Kavli Institute for Particle Astrophysics and Cosmology.

MARIE-EVE NAUD – Ms. Naud is the University of Montreal PhD student who led analysis that recently uncovered a previously unknown giant planet using infrared light. The planet, known as GU Pisces b, is one of the most unusual exoplanets found to-date, with a mass 10 times greater than Jupiter’s and orbiting its star at 2,000 times the distance between Earth and our sun.

KELEN TUTTLE (moderator) – Ms. Tuttle is a freelance journalist with more than a decade of experience in science communications. Most recently, she served as Editor-in-Chief of Symmetry, a magazine dedicated to the science and culture of particle physics. Her fields of expertise also include astrophysics, biology and chemistry.

Tagged as:
exoplanets,
Extrasolar Planets,
Kavli foundation
Posted by Nelio Inacio at 8:38 AM 0 comments
Labels: , ,

Supermassive Black Hole Blasting Molecular Hydrogen Solves Outstanding Mystery

Supermassive Black Hole Blasting Molecular Hydrogen Solves Outstanding Mystery:



An artist's conception of a supermassive black hole's jets. Image Credit: NASA / Dana Berry / SkyWorks Digital

An artist’s conception of a supermassive black hole’s jets. Image Credit: NASA / Dana Berry / SkyWorks Digital
The supermassive black holes in the cores of most massive galaxies wreak havoc on their immediate surroundings. During their most active phases — when they ignite as luminous quasars — they launch extremely powerful and high-velocity outflows of gas.

These outflows can sweep up and heat material, playing a pivotal role in the formation and evolution of massive galaxies. Not only have astronomers observed them across the visible Universe, they also play a key ingredient in theoretical models.

But the physical nature of the outflows themselves has been a longstanding mystery. What physical mechanism causes gas to reach such high speeds, and in some cases be expelled from the galaxy?

A new study provides the first direct evidence that these outflows are accelerated by energetic jets produced by the supermassive black hole.

Using the Very Large Telescope in Chile, a team of astronomers led by Clive Tadhunter from Sheffield University, observed the nearby active galaxy IC 5063. At locations in the galaxy where its jets are impacting regions of dense gas, the gas is moving at extraordinary speeds of over 600,000 miles per hour.

“Much of the gas in the outflows is in the form of molecular hydrogen, which is fragile in the sense that it is destroyed at relatively low energies,” said Tadhunter in a press release. “I find it extraordinary that the molecular gas can survive being accelerated by jets of highly energetic particles moving at close to the speed of light.

As the jets travel through the galactic matter, they disrupt the surrounding gas and generate shock waves. These shock waves not only accelerate the gas, but also heat it. The team estimates the shock waves heat the gas to temperatures high enough to ionize the gas and dissociate the molecules. Molecular hydrogen is only formed in the significantly cooler post-shock gas.

“We suspected that the molecules must have been able to reform after the gas had been completely upset by the interaction with a fast plasma jet,” said Raffaella Morganti from the Kapteyn Institute Groningen University. “Our direct observations of the phenomenon have confirmed that this extreme situation can indeed occur. Now we need to work at describing the exact physics of the interaction.”

In interstellar space, molecular hydrogen forms on the surface of dust grains. But in this scenario, the dust is likely to have been destroyed in the intense shock waves. While it is possible for molecular hydrogen to form without the aid of dust grains (as seen in the early Universe) the exact mechanism in this case is still unknown.

The research helps answer a longstanding question — providing the first direct evidence that jets accelerate the molecular outflows seen in active galaxies — and asks new ones.

The results were published in Nature and are available online.

Tagged as:
Black Hole Jets,
quasars,
supermassive black holes
Posted by Nelio Inacio at 8:37 AM 0 comments

Something In Big Dipper ‘Blob’ Is Sending Out Cosmic Rays, Study Says

Something In Big Dipper ‘Blob’ Is Sending Out Cosmic Rays, Study Says:



A map of cosmic ray concentrations in the northern sky, showing a "hotspot" (red) in the location of the Big Dipper. Credit: K. Kawata, University of Tokyo Institute for Cosmic Ray Research

A map of cosmic ray concentrations in the northern sky, showing a “hotspot” (red) in the location of the Big Dipper. Credit: K. Kawata, University of Tokyo Institute for Cosmic Ray Research
Behind the Big Dipper is something pumping out a lot of extremely high-energy cosmic rays, a new study says. And as astronomers try to learn more about the nature of these emanations — maybe black holes, maybe supernovas — newer work hints that it could be related to how the universe is structured.

It appears that the particles come from spots in the cosmos where matter is densely packed, such as in “superclusters” of galaxies, the researchers stated, adding this is promising progress for tracking down the source of the cosmic rays.

“This puts us closer to finding out the sources – but no cigar yet,” stated University of Utah physicist Gordon Thomson, co-principal investigator for the Telescope Array that performed the observations. “All we see is a blob in the sky, and inside this blob there is all sorts of stuff – various types of objects – that could be the source,” he added. “Now we know where to look.”

The study examined the highest-energy cosmic rays that are about 57 billion billion electron volts (5.7 times 10 to the 19th power), picking that type because it is the least affected by magnetic field lines in space. As cosmic rays interact with the magnetic field lines, it changes their direction and thus makes it harder for researchers to figure out where they came from.

Astrophoto: Ursa Major and Big Dipper Among the Red Clouds by Rajat Sahu

Ursa Major and Big Dipper Among the Red Clouds. Credit: Rajat Sahu
Scientists used a set of 500 detectors called the Telescope Array, which is densely packed in a 3/4 mile (1.2 kilometer) square grid in the desert area of Millard County, Utah. The array recorded 72 cosmic rays between May 11, 2008 and May 4, 2013, with 19 of those coming from the “hotspot” — a circle 40 degrees in diameter taking up 6% of the sky. (Researchers are hoping for funding for an expansion to probe this area in more detail.)

It’s possible the hotspot could be a fluke, but not very possible, the researchers added: there’s a 1.4 in 10,000 chance. And they’re keeping themselves open to many types of sources: “Besides active galactic nuclei and gamma ray emitters, possible sources include noisy radio galaxies, shock waves from colliding galaxies and even some exotic hypothetical sources such as the decay of so-called ‘cosmic strings’ or of massive particles left over from the big bang that formed the universe 13.8 billion years ago,” the researchers stated.

Cosmic rays were first discovered in 1912 and are believed to be hydrogen nuclei or the centers of nuclei from heavier elements like iron or oxygen. The highest-energy ones in the study may come from protons alone, but that’s not clear yet.

The paper is available in preprint version on Arxiv, and has been accepted for publication in Astrophysical Journal Letters.

Source: University of Utah

Tagged as:
Big Dipper,
cosmic rays,
telescope array,
Ursa Major
Posted by Nelio Inacio at 8:36 AM 0 comments

‘Vulnerable’ Earth-Like Planets Could Survive With Friction: Study

‘Vulnerable’ Earth-Like Planets Could Survive With Friction: Study:



Flexible planets: NASA is studying how planets in eccentric orbits flex due to tidal forces. At left is a planet with a thick ice shell, and at right a terrestrial-type planet. Credit: NASA's Goddard Space Flight Center

Flexible planets: NASA is studying how planets in eccentric orbits flex due to tidal forces. At left is a planet with a thick ice shell, and at right a terrestrial-type planet. Credit: NASA’s Goddard Space Flight Center
If you’re a potentially habitable world orbiting in a zone where liquid water can exist — and then a rude gas giant planet happens to disturb your orbit — that could make it difficult or impossible for life to survive.

But even in the newly eccentric state, a new study based on simulations shows that the orbit can be made more circular again quite quickly, taking only a few hundred thousand years to accomplish. The key is the tidal forces the parent star exerts on the planet as it moves in its orbit, flexing the interior and slowing the planet down to a circular orbit.

“We found some unexpected good news for planets in vulnerable orbits,” stated Wade Henning, a University of Maryland scientist who led the work and who is working at NASA’s Goddard Space Flight Center in Maryland. “It turns out these planets will often experience just enough friction to move them out of harm’s way and into safer, more-circular orbits more quickly than previously predicted.“

The transition period wouldn’t be pretty, since NASA states the planets “would be driven close to the point of melting” or have a “nearly melted layer” on them. The interior could also host magma oceans, depending on how intense the friction is. But a softer planet flexes more easily, allowing it to generate heat, bleed that energy off into space and gradually settle into a circular orbit. When tidal heating ceases, then life could possibly take hold.

This artists' rendition shows a super-Earth, or low mass exoplanet, orbiting close to its parent star. Credit: Keck Observatory

This artists’ rendition shows a super-Earth, or low mass exoplanet, orbiting close to its parent star. Credit: Keck Observatory
Another possibility is the eccentric orbit itself may be enough to keep life happy, at least for a while. If the planet is colder and stiffer, and orbiting far from its star, it’s possible the tidal flexing would serve as an energy source for life to survive.

Think of a situation like Europa near Jupiter, where some scientists believe the moon could have a subsurface ocean heated by interactions with the gas giant.

The model covers planets that are between the size of Earth and 2.5 times larger, and future studies will aim to see how layers in the planet change over time.

Source: NASA

Tagged as:
Europa,
super earth,
tidal heating
Posted by Nelio Inacio at 8:36 AM 0 comments

NameExoWorlds, an IAU Worldwide Contest to Name Alien Planets, Continues Controversy

NameExoWorlds, an IAU Worldwide Contest to Name Alien Planets, Continues Controversy:



This artist's impression of an exoplanet currently represents a distant world with an alien name, some long grocery list of numbers. But now, the IAU is giving you the chance to rename it with a little jazz. Image Credit: IAU/M. Kornmesser/N. Risinger (skysurvey.org)

This artist’s impression of an exoplanet currently represents a distant world with an alien name. But now, the IAU is giving you the chance to rename it with a little jazz. Image Credit: IAU / M. Kornmesser / N. Risinger (skysurvey.org)
The International Astronomical Union has unveiled a worldwide contest, NameExoWorlds, which gives the public a role in naming planets and their host stars beyond the solar system.

It’s the latest chapter in a years-long controversy over how celestial objects, including exoplanets, are classified and named.

Although the IAU has presided over the long process of naming astronomical objects for nearly a century, until last year they didn’t feel the need to include exoplanets on this long list.

As late as March 2013, the IAU’s official word on naming exoplanets was: “The IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge.” Since there was seemingly going to be so many exoplanets, the IAU saw it too difficult to name them all.

Other organizations, however, such as the SETI institute and the space company Uwingu leapt at the opportunity to engage the public in providing names for exoplanets. Their endeavors been widely popular with the general public, but generated discussion about how official the names would be.

The IAU issued a later statement in April 2014 (which Universe Today covered with vigor) and claimed that these two campaigns had no bearing on the official naming process. By August 2014, the IAU had introduced new rules for naming exoplanets, drastically changing their stance and surprising many.

Now in partnership with Zooniverse, a citizen-science organization, the IAU has drawn up a list of 305 well-characterized exoplanets in 206 solar systems. Starting in September, astronomy organizations can register for the opportunity to select planets for naming.

In October, the IAU plans to ask the registered organizations to vote for the 20 to 30 worlds on the list that they want to name. The exact number will depend on the number of registered groups. In December, those groups can propose names for the worlds that get the most votes. Groups can only propose names in accordance with the following set of rules. A name must be:

—   16 characters or less in length

—   Preferably one word

—   Pronounceable (in some language)

—   Non-offensive

—   Not too similar to an existing name of an astronomical object

Starting in March 2015, the list of proposed names will be put up to an Internet vote. The winners will be validated by the IAU, and announced during a ceremony at the IAU General Assembly in Honolulu in August 2015.

The popular name for a given exoplanet won’t replace the scientific name. But it will carry the IAU seal of approval.

Astronomer Alan Stern, principal investigator of the New Horizons mission to Pluto and CEO of Uwingu told Universe Today’s Senior Editor, Nancy Atkinson, that he was not surprised by the IAU’s new statement. “To my eye though, it’s just more IAU elitism, they can’t seem to get out of their elitist rut thinking they own the Universe.”

“Uwingu’s model is in our view far superior — people can directly name planets around other stars, with no one having to approve the choices,” Stern continued. “With 100 billion plus planets in the galaxy, why bother with committees of elites telling people what they do and don’t approve of?”

If nothing else, the controversy has sparked multiple venues to name exoplanets and more importantly learn about these alien worlds.

Tagged as:
exoplanets,
IAU,
Uwingu
Posted by Nelio Inacio at 8:35 AM 0 comments

Blast! Sun Pops Off A Moderate Solar Flare. Could Others Follow Soon?

Blast! Sun Pops Off A Moderate Solar Flare. Could Others Follow Soon?:





With a watchful NASA spacecraft capturing its moves, the Sun sent off a “mid-level” solar flare on Tuesday (July 8) that you can watch (over and over again) in the video above. The Solar Dynamics Observatory caught the explosion around 12:20 p.m. EDT (4:20 p.m. UTC), which led into a coronal mass ejection that sent a surge of solar material into space.

Solar flares can be disruptive to Earth communications and also cause auroras in the atmosphere. In this case, the M6 solar flare created “short-lived impacts to high frequency radio communications on the sunlit side of Earth … as a result,” wrote the National Oceanic and Atmospheric Administration in a forecast July 8.

In this case, however, the coronal mass ejection (seen by the Solar Dynamics Observatory) is not expected to hit Earth. But with the Sun around its maximum of solar activity in the 11-year cycle, other eruptions could head into space in the coming days. M is considered a moderate flare and X the strongest kind.

“Solar activity is low, but the quiet is unlikely to persist,” wrote SpaceWeather.com in an update published today (July 10). “There are three sunspots with unstable magnetic fields capable of strong eruptions: AR2108, AR2109, AR2113. NOAA forecasters estimate a 75% chance of M-flares and 15% chance of X-flares on July 10th.”

This flare caused a surge in shortwave activity that you can hear in this audio file, recorded by New Mexico amateur astronomer Thomas Ashcraft. “Radio bursts such as these are sparked by shock waves moving through the sun’s atmosphere,” SpaceWeather added. “Set in motion by flares, these shock waves excite plasma instabilitties that emit static-y radio waves.”

A moderate solar flare erupts on the sun July 8, 2014 in this image from NASA's Solar Dynamics Observatory. The image uses a wavelength of light (131 Angstroms) that emphasizes the hot material of the sun. Credit: NASA/SDO

A moderate solar flare erupts on the sun July 8, 2014 in this image from NASA’s Solar Dynamics Observatory. The image uses a wavelength of light (131 Angstroms) that emphasizes the hot material of the sun. Credit: NASA/SDO
Tagged as:
coronal mass ejection,
solar flare
Posted by Nelio Inacio at 8:34 AM 0 comments

Merging Giant Galaxies Sport ‘Blue Bling’ in New Hubble Pic

Merging Giant Galaxies Sport ‘Blue Bling’ in New Hubble Pic:



In this new Hubble image shows two galaxies (yellow, center) from the cluster SDSS J1531+3414 have been found to be merging into one and a "chain" of young stellar super-clusters are seen winding around the galaxies's nuclei. The galaxies are surrounded by an egg-shaped blue ring caused by the immense gravity of the cluster bending light from other galaxies beyond it. Credit: NASA/ESA/Grant Tremblay

In this new Hubble image shows two galaxies (yellow, center) from the cluster SDSS J1531+3414 have been found to be merging into one and a “chain” of young stellar super-clusters are seen winding around the galaxies’s nuclei. The galaxies are surrounded by an egg-shaped blue ring caused by the immense gravity of the cluster bending light from other galaxies beyond it. Credit: NASA/ESA/Grant Tremblay
On a summer night, high above our heads, where the Northern Crown and Herdsman meet, a titanic new galaxy is being born 4.5 billion light years away. You and I can’t see it, but astronomers using the Hubble Space Telescope released photographs today showing the merger of two enormous elliptical galaxies into a future  heavyweight adorned with a dazzling string of super-sized star clusters.

The two giants, each about 330,000 light years across or more than three times the size of the Milky Way, are members of a large cluster of galaxies called SDSS J1531+3414. They’ve strayed into each other’s paths and are now helpless against the attractive force of gravity which pulls them ever closer.

A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)

A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)
Galactic mergers are violent events that strip gas, dust and stars away from the galaxies involved and can alter their appearances dramatically, forming large gaseous tails, glowing rings, and warped galactic disks. Stars on the other hand, like so many pinpoints in relatively empty space, pass by one another and rarely collide.

Elliptical galaxies get their name from their oval and spheroidal shapes. They lack the spiral arms, rich reserves of dust and gas and pizza-like flatness that give spiral galaxies like Andromeda and the Milky Way their multi-faceted character. Ellipticals, although incredibly rich in stars and globular clusters, generally appear featureless.

The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. Credit: NASA/ESA

The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. What look like stars around M87 are really globular star clusters. Credit: NASA/ESA
But these two monster ellipticals appear to be different. Unlike their gas-starved brothers and sisters, they’re rich enough in the stuff needed to induce star formation. Take a look at that string of blue blobs stretching across the center – astronomers call it a great example of ‘beads on a string’ star formation. The knotted rope of gaseous filaments with bright patches of new star clusters stems from the same physics which causes rain or water from a faucet to fall in droplets instead of streams. In the case of water, surface tension makes water ‘snap’ into individual droplets; with clouds of galactic gas, gravity is the great congealer.

Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click for the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay

Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click to read the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay
Nineteen compact clumps of young stars make up the length of this ‘string’, woven together with narrow filaments of hydrogen gas. The star formation spans 100,000 light years, about the size of our galaxy, the Milky Way. Astronomers still aren’t sure if the gas comes directly from the galaxies or has condensed like rain from X-ray-hot halos of gas surrounding both giants.

The blue arcs framing the merger have to do with the galaxy cluster’s enormous gravity, which warps the fabric of space like a lens, bending and focusing the light of more distant background galaxies into curvy strands of blue light. Each represents a highly distorted image of a real object.



Simulation of the Milky Way-Andromeda collision 4 billion years from now

Four billion years from now, Milky Way residents will experience a merger of our own when the Andromeda Galaxy, which has been heading our direction at 300,000 mph for millions of years, arrives on our doorstep. After a few do-si-dos the two galaxies will swallow one another up to form a much larger whirling dervish that some have already dubbed ‘Milkomeda’. Come that day, perhaps our combined galaxies will don a string a blue pearls too.

Tagged as:
elliptical,
galaxy,
Hubble,
merger,
Milkomeda,
SDSS J1531+3414,
spiral
Posted by Nelio Inacio at 8:33 AM 0 comments

How to Tell the Age of a Sun-like Star? Try ‘Gyrochronology’

How to Tell the Age of a Sun-like Star? Try ‘Gyrochronology’:



Credit: NASA/European Space Agency

Our active Sun. Image Credit: NASA / European Space Agency
There’s no doubt the term “Earth-like” is a bit of a misnomer. It requires only that a planet is both Earth-size (less than 1.25 times Earth’s girth and less than twice Earth’s mass) and circles its host star within the habitable zone.

But defining a “Sun-like” star may be just as difficult. A solar twin should have a temperature, mass, age, radius, metallicity, and spectral type similar to the Sun. Although measuring most of these factors isn’t easy, aging a star is extremely difficult, and astronomers tend to ignore it when concluding if a star is Sun-like or not.

This is less than ideal, given that our Sun and all stars change over time. Thankfully a technique — gyrochronology — is allowing astronomers to measure stellar ages based only on spin and find true solar analogues.

“We have found stars with properties that are close enough to those of the Sun that we can call them ‘solar twins,’” said lead author Jose Dias do Nascimento from the Harvard-Smithsonian Center for Astrophysics (CfA) in a press release.

do Nascimento and colleagues measured the spin of 75 stars by looking for changes in brightness caused by dark star spots, rotating in and out of view. Although this difference is minute, clocking in at a few percent or less, NASA’s Kepler spacecraft excels at extracting such small changes in brightness.

On average, the sampled stars spin once every 19 days, compared to the 25-day rotation period of the Sun. This makes most of the stars slightly younger than the Sun, as younger stars spin faster than older ones.

The relationship between stellar spin and age was determined in previous research by Soren Meibom (CfA) and colleagues, who measured the rotation rates for stars in a one-billion-year-old cluster. Since the stars already had a known age, the team could measure their spin rates and calibrate the previous relationship.

Using this method, do Nascimento and colleagues found 22 true solar analogues within their data set of 75 stars.

“With solar twins we can study the past, present, and future of stars like our Sun,” said do Nascimento. “Consequently, we can predict how planetary systems like our solar system will be affected by the evolution of their central stars.”

The results were accepted for publication in The Astrophysical Journal Letters and are available online.

Tagged as:
gyrochronology,
Stellar Aging
Posted by Nelio Inacio at 8:32 AM 0 comments

Water Or Not? Fresh Martian Trenches Primarily Due To Carbon Dioxide Freezes, Study Says

Water Or Not? Fresh Martian Trenches Primarily Due To Carbon Dioxide Freezes, Study Says:



Mars Reconnaissance Orbiter

Artist Illustration of the Mars Reconnaissance Orbiter
Does liquid water currently flow on the surface of Mars? Fresh-looking trenches on the Red Planet have come under a lot of scrutiny, including a 2010 study concluding that 18 dune gullies were primarily formed by carbon dioxide freezing.

A new study looking at several more gullies comes to about the same conclusion. Researchers examined images of 356 sites, with each of these sites captured multiple times on camera. Of the 38 of these sites that showed changes since 2006, the researchers concluded site changes happened in the winter — when it’s too cold for any liquid water to flow.

“As recently as five years ago, I thought the gullies on Mars indicated activity of liquid water,” stated lead author Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center in Arizona.

“We were able to get many more observations, and as we started to see more activity and pin down the timing of gully formation and change, we saw that the activity occurs in winter.”

Observations were made using NASA’s long-running Mars Reconnaissance Orbiter mission, which has been in orbit there since 2006. The researchers said that these lengthy missions are important for examining and confirming findings, because they can revisit data over time and change their conclusions, as needed, as more evidence comes in. Pictures were taken by the High Resolution Imaging Science Experiment (HiRISE) camera.

A 164-yard (150-meter) wide swath of Martian surface at 37.7 degrees south latitude, 192.9 degrees east longitude shows gullies changing between passes of the Mars Reconnaissance Orbiter. The earlier image, at left, was taken May 30, 2007. Near the arrows on the image on right, which was taken May 31, 2013, is a "rubbly flow" near the channel's mouth. Credit: NASA/JPL-Caltech/Univ. of Arizona

A 164-yard (150-meter) wide swath of Martian surface at 37.7 degrees south latitude, 192.9 degrees east longitude shows gullies changing between passes of the Mars Reconnaissance Orbiter. The earlier image, at left, was taken May 30, 2007. Near the arrows on the image on right, which was taken May 31, 2013, is a “rubbly flow” near the channel’s mouth. Credit: NASA/JPL-Caltech/Univ. of Arizona
The first images of gullies in 2000 sparked speculation that liquid water could be responsible for changing the surface today. It’s true that Mars has water frozen in its poles, and observations with several NASA rovers show strong evidence that water once flowed on the surface. But, these trenches are unlikely to show evidence that liquid water is flowing right now.

“Frozen carbon dioxide, commonly called dry ice, does not exist naturally on Earth, but is plentiful on Mars. It has been linked to active processes on Mars such as carbon dioxide gas geysers and lines on sand dunes plowed by blocks of dry ice,” NASA stated.

“One mechanism by which carbon-dioxide frost might drive gully flows is by gas that is sublimating from the frost providing lubrication for dry material to flow. Another may be slides due to the accumulating weight of seasonal frost buildup on steep slopes.”

The team added that smaller features could be the result of liquid water, such as this recent study using MRO. It’ll be interesting to see what other data is churned up as the fleet of orbiters continues making observations, and other scientists weigh in on the results.

The work will be published in the journal Icarus.

Source: Jet Propulsion Laboratory

Tagged as:
High Resolution Imaging Science Experiment (HiRISE),
mars reconnaissance orbiter
Posted by Nelio Inacio at 8:31 AM 0 comments

Found! Seven Dwarfs Surround The ‘Pinwheel Galaxy’ Field Of View

Found! Seven Dwarfs Surround The ‘Pinwheel Galaxy’ Field Of View:



This Hubble image reveals the gigantic Pinwheel Galaxy (M101), one of the best known examples of "grand design spirals," and its supergiant star-forming regions in unprecedented detail. Astronomers have searched galaxies like this in a hunt for the progenitors of Type Ia supernovae, but their search has turned up mostly empty-handed. Credit: NASA/ESA

This Hubble image reveals the gigantic Pinwheel Galaxy (M101), one of the best known examples of “grand design spirals”. Credit: NASA/ESA
Using a unique type of telescope that includes long-range lenses, astronomers at Yale University have found seven dwarf galaxies surrounding the well-known Pinwheel Galaxy, M101.

It’s unclear if the septuplets are actually orbiting the pinwheel, or just happen to be in the same field of view. But astronomers at Yale say that this shows the so-called Dragonfly Telephoto Array is working well, and they are planning follow-up observations to see what else they can find.

“The previously unseen galaxies may yield important insights into dark matter and galaxy evolution, while possibly signaling the discovery of a new class of objects in space,” Yale University stated in a release.

The galaxies escaped detection before because their light is so diffuse, but this is what the telescope is designed to pick up. The telescope is constructed of eight telephoto lenses (similar to what you would use to photograph a sporting event) that include “special coating” to stop any light from scattering inside. The telescope is called “Dragonfly” because like an insect, it has multiple eyes for looking at things.

Seven new dwarf galaxies shine in the field of view surrounding M101, the Pinwheel Galaxy. Credit: Yale University

Seven new dwarf galaxies shine in the field of view surrounding M101, the Pinwheel Galaxy. Credit: Yale University
Follow-up observations will come with the Hubble Space Telescope. If it turns out that these galaxies are not bound to M101, the results will be equally interesting to astronomers.

“There are predictions from galaxy formation theory about the need for a population of very diffuse, isolated galaxies in the universe,” stated Allison Merritt, a Yale graduate student who led the research.

“It may be that these seven galaxies are the tip of the iceberg, and there are thousands of them in the sky that we haven’t detected yet.”

The research was published in Astrophysical Journal Letters and is also available in preprint version on Arxiv.

Source: Yale University

The Dragonfly Telephoto Array, a unique Yale University telescope used to look for diffuse light in galaxies. Credit: Yale University

The Dragonfly Telephoto Array, a unique Yale University telescope used to look for diffuse light in galaxies. Credit: Yale University
Tagged as:
dragonfly telephoto array,
M101,
Pinwheel Galaxy
Posted by Nelio Inacio at 8:30 AM 0 comments

Contest: Get Your Video On The International Space Station

Contest: Get Your Video On The International Space Station:



A view of the International Space Station as seen by the last departing space shuttle crew, STS-135. Credit: NASA

A view of the International Space Station as seen by the last departing space shuttle crew, STS-135. Credit: NASA
If you’re starting your career, good with a video and love space, here’s your big chance to showcase your work in an exclusive screening location — the International Space Station! A new Lunar and Planetary Institute-led contest is inviting people to send in their videos to talk about how space helps out humanity. More details below the jump.

“Through the international Humans in Space Art Challenge, we invite you to explore ‘How will humans use space science, and technology to benefit humanity?’ and to express your answer creatively in a video three minutes long or less,” reads the description of the challenge.

“Video artwork can be of any style, featuring original animation, sketches, music, live action drama, poetry, dance, Rube Goldberg machines, apps, etc. … Individuals or teams of participants should include one clear reference to the International Space Station in their videos and can use space station footage if desired.”

The contest is open to “college students and early career professionals”, according to the webpage. The due date for the challenge is Nov. 15, 2014. Full requirements and contact information for the contest organizers are available on this page.
Posted by Nelio Inacio at 8:29 AM 0 comments

New VLT Observations Clear Up Dusty Mystery

New VLT Observations Clear Up Dusty Mystery:



The dwarf galaxy UGC 5189A, site of the supernova SN 2010jl. Image Credit: ESO

The dwarf galaxy UGC 5189A, site of the supernova SN 2010jl. Image Credit: ESO
The Universe is overflowing with cosmic dust. Planets form in swirling clouds of dust around a young star; Dust lanes hide more-distant stars in the Milky Way above us; And molecular hydrogen forms on the dust grains in interstellar space.

Even the soot from a candle is very similar to cosmic carbon dust. Both consist of silicate and amorphous carbon grains, although the size grains in the soot are 10 or more times bigger than typical grain sizes in space.

But where does the cosmic dust come from?

A group of astronomers has been able to follow cosmic dust being created in the aftermath of a supernova explosion. The new research not only shows that dust grains form in these massive explosions, but that they can also survive the subsequent shockwaves.

Stars initially draw their energy by fusing hydrogen into helium deep within their cores. But eventually a star will run out of fuel. After slightly messy physics, the star’s contracted core will begin to fuse helium into carbon, while a shell above the core continues to fuse hydrogen into helium.

The pattern continues for medium to high mass stars, creating layers of different nuclear burning around the star’s core. So the cycle of star birth and death has steadily produced and dispersed more heavy elements throughout cosmic history, providing the substances necessary for cosmic dust.

“The problem has been that even though dust grains composed of heavy elements would form in supernovae, the supernova explosion is so violent that the grains of dust may not survive,” said coauthor Jens Hjorth, head of the Dark Cosmology Center at the Niels Bohr Institute in a press release. “But cosmic grains of significant size do exist, so the mystery has been how they are formed and have survived the subsequent shockwaves.”

The team led by Christa Gall used ESO’s Very Large Telescope at the Paranal Observatory in northern Chile to observe a supernova, dubbed SN2010jl, nine times in the months following the explosion, and for a tenth time 2.5 years after the explosion. They observed the supernova in both visible and near-infrared wavelengths.

SN2010jl was 10 times brighter than the average supernova, making the exploding star 40 times the mass of the Sun.

“By combining the data from the nine early sets of observations we were able to make the first direct measurements of how the dust around a supernova absorbs the different colours of light,” said lead author Christa Gall from Aarhus University. “This allowed us to find out more about the dust than had been possible before.”

The results indicate that dust formation starts soon after the explosion and continues over a long time period.

The dust initially forms in material that the star expelled into space even before it exploded. Then a second wave of dust formation occurs, involving ejected material from the supernova. Here the dust grains are massive — one thousandth of a millimeter in diameter — making them resilient to any following shockwaves.

“When the star explodes, the shockwave hits the dense gas cloud like a brick wall. It is all in gas form and incredibly hot, but when the eruption hits the ‘wall’ the gas gets compressed and cools down to about 2,000 degrees,” said Gall. “At this temperature and density elements can nucleate and form solid particles. We measured dust grains as large as around one micron (a thousandth of a millimeter), which is large for cosmic dust grains. They are so large that they can survive their onward journey out into the galaxy.”

If the dust production in SN2010jl continues to follow the observed trend, by 25 years after the supernova explosion, the total mass of dust will have half the mass of the Sun.

The results have been published in Nature and are available for download here. Niels Bohr Institute’s press release and ESO’s press release are also available.

Tagged as:
Dust formation,
Supernovae,
Very Large Telescope
Posted by Nelio Inacio at 8:29 AM 0 comments

Comet Jacques Is Back! Joins Venus and Mercury at Dawn

Comet Jacques Is Back! Joins Venus and Mercury at Dawn:



Will you see it? Comet Jacques will pass about 3.5 degrees north of brilliant Venus tomorrow morning July 13. This map shows the sky facing northeast about 1 hour before sunrise. Stellarium

Will you see it? Comet Jacques will pass about 3.5 degrees north of brilliant Venus tomorrow morning July 13. This map shows the sky facing northeast about 1 hour before sunrise when the comet will be 10° high in the northeastern sky. Stellarium
Comet C/2014 E2 Jacques has returned! Before it disappeared in the solar glow this spring, the comet reached magnitude +6, the naked eye limit. Now it’s back at dawn, rising higher each morning as it treks toward darker skies. Just days after its July 2 perihelion, the fuzzball will be in conjunction with the planet Venus tomorrow morning July 13. With Mercury nearby, you may have the chance to see this celestial ‘Rat Pack’ tucked within a 8° circle.

First photo of Comet Jacques on its return to the morning sky taken on July 7. Credit: Gerald Rhemann

First photo of Comet Jacques on its return to the morning sky taken on July 11. Two tails are visible – a short, dust tail pointing to the lower left of the coma and longer gas or ion tail to the right. Credit: Gerald Rhemann
While I can guarantee you’ll see Venus and probably Mercury (especially if you use binoculars), morning twilight and low altitude will undoubtedly make spotting Comet Jacques challenging. A 6-inch telescope might nail it. Look for a small, fuzzy cloud with a brighter core against the bluing sky. Patience is the sky observer’s most useful tool. It won’t be long before the comet’s westward motion combined with the seasonal drift of the stars will loft it into darkness again.

Use this map to follow Comet Jacques as it moves west across Taurus and Auriga over the next few weeks. Planet positions are shown for July 13 with stars to magnitude +6. Jacques' position is marked every 5 days. Source: Chris Mariott's SkyMap

Use this map to follow Comet Jacques as it moves west across Taurus and Auriga over the next few weeks. Planet positions are shown for July 13 with stars to magnitude +6. Jacques’ position is marked every 5 days. Click to enlarge. Source: Chris Mariott’s SkyMap
A week from now, when the moon’s slimmed to half, the comet will be nearly twice as high and should be easily visible in 50mm binoculars at the start of morning twilight.

Comet Jacques is expected to remain around magnitude +6 through the remainder of July into early August and then slowly fade. It will be well-placed in Perseus at the time of the Perseid meteor shower on Aug. 12-13. Closest approach to Earth occurs on August 29 at 52.4 million miles (84.3 million km). Good luck and let us know if you see it.

Tagged as:
comet jacques,
Mercury,
Venus
Posted by Nelio Inacio at 8:28 AM 0 comments

Into The Black? Maybe Radio Bursts Are From Outside The Galaxy After All, Study Says

Into The Black? Maybe Radio Bursts Are From Outside The Galaxy After All, Study Says:



Image of the sky where the radio burst FRB 121102 was found, in the constellation Auriga. You can see its location with a green circle. At left is supernova remnant S147 and at right, a star formation area called IC 410. Credit: Rogelio Bernal Andreo (DeepSkyColors.com)

Image of the sky where the radio burst FRB 121102 was found, in the constellation Auriga. You can see its location with a green circle. At left is supernova remnant S147 and at right, a star formation area called IC 410. Credit: Rogelio Bernal Andreo (DeepSkyColors.com)
Where are these radio bursts coming from? Astronomers have heard these signals from the sky several times, but always with the same telescope (Parkes Observatory in Australia). There was debate about whether these were coming from inside or outside the galaxy, or even from Earth itself (given only the one observatory was detecting them.)

A new study with a different telescope, the Arecibo Observatory in Puerto Rico, concludes that the bursts are from outside the galaxy. This is the first time one of these bursts have been found in the northern hemisphere of the sky.

“Our result is important because it eliminates any doubt that these radio bursts are truly of cosmic origin,” stated Victoria Kaspi, an astrophysics researcher at McGill University who participated in the research. “The radio waves show every sign of having come from far outside our galaxy – a really exciting prospect.”

Fast radio bursts are a flurry of radio waves that last a few thousandths of a second, and at any given minute there are only seven of these in the sky on average, according to the Max Planck Institute for Radio Astronomy. Their cause is unknown. They could be anything from black holes, to neutron stars coming together, to the magnetic field of pulsars (a type of neutron star) flaring up — or something else.

Arecibo Observatory in Puerto Rico. Credit: NAIC - Arecibo Observatory, a facility of the NSF

Arecibo Observatory in Puerto Rico. Credit: NAIC – Arecibo Observatory, a facility of the NSF
The pulse was found Nov. 2, 2012 in the constellation Auriga. Astronomers believe it is from quite far away from measuring its plasma dispersion, or the slowdown of radio waves as they crash into interstellar electrons. This particular source had triple the maximum dispersion than what would be found inside the galaxy, astronomers stated.

“The brightness and duration of this event, and the inferred rate at which these bursts occur, are all consistent with the properties of the bursts previously detected by the Parkes telescope in Australia,” stated Laura Spitler, who led the research. (She was at Cornell University when the study began, but is now at the Max Planck Institute for Radio Astronomy in Bonn, Germany.)

But other research has been back-and-forth on whether these are actually extragalactic bursts. One 2013 paper supposed it could be colliding neutron stars from far away, while another said it could instead be nearby stars flaring up.

The research was published in the Astrophysical Journal and is also available in preprint version on Arxiv.

Source: McGill University and the Max Planck Institute for Radio Astronomy

Tagged as:
arecibo observatory,
fast radio burst,
radio burst
Posted by Nelio Inacio at 8:27 AM 0 comments

Your Weekend ‘SuperMoon’ Photos from Around the World

Your Weekend ‘SuperMoon’ Photos from Around the World:



The big proxigean full Moon rises over Daganzo de Arriba, near Madrid, Spain on July 12, 2014. Credit and copyright: Alvaro Ibañez Perez.

The big proxigean full Moon rises over Daganzo de Arriba, near Madrid, Spain on July 12, 2014. Credit and copyright: Alvaro Ibañez Perez.
Did you hear there was something special about the full Moon this weekend… that it would be, well… really super? I heard about it on every newscast I watched or listened to. Even xkcd got into the ‘Supermoon’ craze. The July “Buck” Moon was the first of three Supermoons on tap for 2014, where the Moon is at its perigee, the closest point to Earth in its orbit, close to the time when it is “officially” full.

If you didn’t hear about it, (or weren’t paying attention) you may not have noticed anything different, as its not radically different from a regular full Moon. Read all the detail of what a Supermoon is here. But as Geoff Chester of the US Naval Observatory, said on NASA’s website, “However, if it gets people out and looking at the night sky and maybe hooks them into astronomy, then it’s a good thing,”

And people were out with their cameras, too! Here’s a great collection of full Moon images from this weekend, as seen in our Flickr Gallery.

An over-exposed beauty showing the full Moon rising through the clouds on July 12, 2014 near Bromsgrove, England, United Kingdom. Credit and copyright: Sarah and Simon Fisher.

An over-exposed beauty showing the full Moon rising through the clouds on July 12, 2014 near Bromsgrove, England, United Kingdom. Credit and copyright: Sarah and Simon Fisher.
The rising "super moon" of July 12, 2014, rising above a canola field in southern Alberta, Canada. Credit and copyright: Alan Dyer/Amazing Sky Photography.

The rising “super moon” of July 12, 2014, rising above a canola field in southern Alberta, Canada. Credit and copyright: Alan Dyer/Amazing Sky Photography.
A Mississippi Super Moonscape on July 12, 2014. Credit and Copyright: Veronica M Photography.

A Mississippi Super Moonscape on July 12, 2014. Credit and Copyright: Veronica M Photography.
The 'Supermoon' setting on the morning of July 13, 2014 at around 6 am local time near Kapiolani, Honolulu, Hawaii. Credit and copyright: Henry Weiland.

The ‘Supermoon’ setting on the morning of July 13, 2014 at around 6 am local time near Kapiolani, Honolulu, Hawaii. Credit and copyright: Henry Weiland.
A 3-exoposure of the full Moon on July 12, 2014, taken near Cap-Rouge, Quebec City, Quebec, Canada. Credit and copyright: Denis Marquis.

A 3-exoposure of the full Moon on July 12, 2014, taken near Cap-Rouge, Quebec City, Quebec, Canada. Credit and copyright: Denis Marquis.
The July 12, 2014 Supermoon or perigee full moon shares the night sky with fireworks from a display in Chester, New York. Credit and copyright: Tom Bushey.

The July 12, 2014 Supermoon or perigee full moon shares the night sky with fireworks from a display in Chester, New York. Credit and copyright: Tom Bushey.
Moonrise with a flyby. July 13, 2014 from the UK. Credit and copyright: SculptorLil on Flickr.

Moonrise with a flyby. July 13, 2014 from the UK. Credit and copyright: SculptorLil on Flickr.
The rising waning Moon on July 13, 2014, from near Bedfordshire, UK. Credit and copyright: DawnSunrise on Flickr.

The rising waning Moon on July 13, 2014, from near Bedfordshire, UK. Credit and copyright: DawnSunrise on Flickr.
Thanks to everyone who submitted images! Check out even more great images in Universe Today’s Flickr Group!



Be advised that this month’s big full Moon was not the closest of the year. The closest Full Moon of 2014 occurs next month on August 10th at 18:11 Universal Time (UT) or 1:44 PM EDT. On that date, the Moon reaches perigee or its closest approach to the Earth at 356,896 kilometres distant at 17:44, less than an hour from Full.

Tagged as:
Moon,
Supermoon,
supermoon 2014
Posted by Nelio Inacio at 8:26 AM 0 comments

A Stunning Image of our Home Star

A Stunning Image of our Home Star:



Sunspots and a detached prominence photographed on July 11, 2014. (© Alan Friedman, All Rights Reserved.)

Sunspots and a detached prominence photographed on July 11, 2014. (© Alan Friedman, All Rights Reserved.)
Active regions 2108 and 2109 are now passing around the limb of the Sun, but not before solar photography specialist Alan Friedman grabbed a few pictures of them on Friday!   The image above, captured by Alan from his location in Buffalo, NY, shows the two large sunspots nestled in a forest of solar spicules while a large detached prominence hovers several Earth-diameters inside the corona. A beautiful snapshot of our home star!

Captured in hydrogen-alpha wavelengths, the image above has been colored by Alan, rotated 90 degrees counterclockwise, and inverted from the original. The sunspots and standing prominence are cooler in Ha than the surrounding chromosphere and corona, and so actually photograph darker.

A view of sunspot 2109 in visible light can be seen below:

AR2109 photographed by Alan Friedman on July 11, 2014.

AR2109 photographed by Alan Friedman on July 11, 2014.
Sunspots are the result of magnetic fields rising up from deep within the Sun, preventing convection from occurring in large areas on the Sun’s surface and thereby creating relatively cooler regions we see as dark spots. They can often be many times the size of Earth and can be sources of powerful solar flares.

See these and more images by Alan on his blog here.

Images © Alan Friedman. All rights reserved.

Tagged as:
Alan Friedman,
astrophotography,
hydrogen alpha,
prominence,
Star,
sun,
sunspot
Posted by Nelio Inacio at 8:25 AM 0 comments

DARPA’s Experimental Space Plane XS-1 Starts Development

DARPA’s Experimental Space Plane XS-1 Starts Development:



Concept images for DARPA’s Experimental Spaceplane (XS-1) program. Credit: DARPA.

Concept images for DARPA’s Experimental Spaceplane (XS-1) program. Credit: DARPA.
The Defense Advanced Research Projects Agency (DARPA) is looking to develop a fully-reusable unmanned spaceplane, and they are now ready to start working their proposed Experimental Spaceplane (XS-1). The agency has put together a “special forces” of sorts in the space industry, awarding prime contracts for the first phase of development to a combination of six companies. These six are a combination of “old” and “new” space companies and are:



The Boeing Company (working with Blue Origin, LLC)

Masten Space Systems (working with XCOR Aerospace)

Northrop Grumman Corporation (working with Virgin Galactic)

“We chose performers who could prudently integrate existing and up-and-coming technologies and operations, while making XS-1 as reliable, easy-to-use and cost-effective as possible,” Jess Sponable, DARPA program manager. “We’re eager to see how their initial designs envision making spaceflight commonplace—with all the potential military, civilian and commercial benefits that capability would provide.”



Each commercial entity will be able to outline their vision of the XS-1, but DARPA wants the the spaceplane to provide aircraft-like access to space for deploying small satellites to orbit and it its development, they’d like to create technology for next-generation hypersonic vehicles, — and do it more affordably.

They envision that a reusable first stage would fly to hypersonic speeds at a suborbital altitude. Then, one or more expendable upper stages would separate and deploy a satellite into low Earth orbit (LEO). The reusable first stage would then return to earth, land and be prepared for the next flight.

Key to the development, DARPA says, are modular components, durable thermal protection systems and automatic launch, flight and recovery systems that should significantly reduce logistical needs, enabling rapid turnaround between flights.

DARPA’s key technical goals for the XS-1 include flying 10 times in 10 days, flying to Mach 10+ at least once and launching a representative small payload to orbit. The program also seeks to reduce the cost of access to space for 3,000- to 5,000-pound payloads to less than $5 million per flight.

Source: DARPA

Tagged as:
DARPA,
XS-1
Posted by Nelio Inacio at 8:24 AM 0 comments
Subscribe to: Posts (Atom)